cache pygments load (#96)

* cache pygments load * fix cache import * linting * replace "nocover"

Author: samuelcolvin

devtools/prettier.py

@@ -5,6 +5,13 @@
 
 from .utils import DataClassType, LaxMapping, SQLAlchemyClassType, env_true, isatty
 
+try:
+ from functools import cache
+except ImportError:
+ from functools import lru_cache
+
+ cache = lru_cache()
+
 __all__ = 'PrettyFormat', 'pformat', 'pprint'
 MYPY = False
 if MYPY:
@@ -28,6 +35,7 @@ class SkipPretty(Exception):
  pass
 
 
+@cache
 def get_pygments():
  try:
  import pygments